Complexes formed between HMG-17 and chromatin in vitro will be treated with chemical cross-linking reagents. Covalently linked heterodimers consisting of HMG-17 and other chromosomal proteins will be isolated from the resulting complexes and identified. The ability of micrococcal nuclease and DN'ase I to release the HMG-17 from the complexes both before and after cross-linking will also be investigated. On the basis of these results, we will attempt to characterize the sites on the chromatin structure to which HMG-17 binds.